In order to maintain the highly functional performance of such mechanical heavy types of vehicles as dredger, bulldozer or a truck-mounted crane, a continual maintenance work has to be conducted daily. The aforesaid continual maintenance work generally denotes fuelling, water adding or checking of spare parts and components, particularly important in denoting the lubricating maintenance of greasing.
The mechanical instrument and method for greasing currently available are as follows: Firstly, there is a "a portable small cylindrical grease gun". Prior to using such an instrument, the grease has first to be dugged from the barrel in which the grease is kept by hand and then filled into the portable small cylindrical grease gun. Screw the lid tightly. Then injected the grease through the mouth of the grease gun by pressing both hands. In such a process, the scratching of grease and the filling of it are all conducted by hand and after that the hand has to be washed before the application of the grease can be conducted, resulting not only in causing not only a lot of troubles but also in causing serious pollution. Secondly, there is a "two-person operated barrel type of grease injection device attached with an extended rubber tube. In another case if two persons are involved in the operation by means of using the structure of an air compressor, in which a continual pressing of the pressing rod in the barrel has to be conducted by a person, while the injection of grease has to be conducted by another person who carried the grease gun in his hand dragging the rubber tube behind him in climbing up onto or going underneath a truck or a motor vehicle, which not only wasted the manpower of one more worker, but also made the motion of moving about unappropriate to cope with the actual requirement of grease injection, particularly when the center of the grease inside the barrel (that is, the position close to the periphery of the pump has been sucked into a state of vacuum which made continual suction of grease impossible. As a remedy, the grease which is located at the periphery has to be scratched by hand and pushed to the center in proximity of the suction jet cylinder resulting in the hand of the worker thoroughly stained with grease and, cleaning of the hand should first be done before further application of grease can be processed. In some cases, heavy oil is added to the grease for dilution purpose which, however, will considerably reduce the quality of the grease as well as the degree of its lubricity. Therefore, this is not regarded as a suitable method. In view of the foregoing defects, the inventor kept on researching in pursuance of rennovation, and managed for the first time the presentation of the structure of a set of "grease scratching/collecting harrow" to replace the aforesaid function which is formerly processed by hand. The said set of structure will enable the grease to be continually sucked and supplied by the pump to allow the injection process to be conducted at the outside of the grease barrel, wherein a hand like "grease scratching-collecting harrow" in the interior will conduct the process of scratching and collecting of the grease which lies at the outer periphery to the proximity of the center (the pump) to be pumped and supplied continually for grease injection. It is so arranged that in the entire process of grease pumping until the end when the grease in the barrel has been wholly consumed, the touching of grease by hand will not be needed and the original quality of the grease can also be maintained.